Estrogen metabolism in normal subjects and selected patients will be studied by new techniques in order to explore normal physiology and test hypotheses regarding pathological conditions throughout the pediatric age range. This project proposes to develop a new method, based on pilot studies already done, for quantitation of urinary estrogens based on Sephadex LH-20 chromatography and radioimmunoassay. This will permit for the first time a reasonably simple technique for precise measurement of the principal estrogens in low level (i.e., prepubertal) urines. The technique will be used in conjunction with a method already in operation in my laboratory for quantitation of circulation (serum) estrone, estradiol, and estriol. In addition, the percent dialyzable ("free") estradiol will be measured in serum. An attempt will also be made to develop a procedure for estimation of estradiol production rates based on the principle of dilution of deuterium labeled estradiol. This procedure would obviate the use of radioisotopes for determination of the production rate of estradiol in pediatric subjects, and would serve as a prototype for estimation of steroid production rates in children without the use of radioactive substances.